Thermoplastic resin composition

ABSTRACT

Disclosed are thermoplastic resin compositions, comprising: 
     (a) a polyphenylene ether resin or a resin composition containing a polyphenylene ether, 
     (b) a modified propylene polymer, or a propylene based resin composition containing the modified propylene polymer and/or a propylene polymer, and 
     (c) optionally, a rubbery substance, wherein the proportion of the component (a) to the sum of the components (a) and (b) is 1 to 90% by weight, and that of the component (b) to the sum of the components (a) and (b) is 99 to 10% by weight, and when the component (c) is present, the proportion of the component (c) to the sum of the components (a) and (b) is 1 to 50 parts by weight per 100 parts by weight of (a) plus (b).

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a novel thermoplastic resin composition whichcan be utilized as a material for producing molded articles by injectionmolding, extrusion molding or a like means.

2. Prior Art

Generally, polyphenylene ethers are excellent in heat resistance, hotwater resistance, dimension stability, and mechanical and electricalproperties. On the other hand, they have disadvantages; for example,they show unsatisfactory moldability due to their high melt viscosity,poor chemical resistance, and low impact resistance.

Known methods for improving moldability by lowering the melt viscosityof polyphenylene ethers while maintaining their excellent propertiesinclude use of a mixture of a polyphenylene ether and a polystyreneresin. However, these known methods still fail to improve chemicalresistance.

On the other hand, propylene polymers are not only excellent in variousproperties such as moldability, toughness, water resistance, chemicalresistance, etc. but also they have low specific gravity and are cheapin cost; they have been widely used as a material for preparing variousmolded articles, films, sheets, etc.

However, the propylene polymers have defects or points which need to beimproved in heat resistance, rigidity, impact resistance, coatability,adhesiveness, etc., which makes an obstacle in developing new practicalutility. In particular, improvement in the heat resistance and impactresistance thereof is strongly desired.

Naturally, it may be expected to blend a polyphenylene ether and apropylene polymer to prepare a resin composition which could have theadvantages of the both polymers and which could have improvedmoldability and impact resistance, and thus a wide possibility of newapplication would be open.

Blending a polyphenylene with a propylene polymer, however, actuallygives rise to a resin composition in which miscibility of the bothpolymers is poor so that molded articles obtained from such a blend asby injection molding suffers phase separation between the polyphenyleneether and the propylene polymer, thereby providing articles havingextremely poor appearance and poor mechanical properties, which areunsatisfactory for practical purposes.

A method for improving the miscibility between a polyphenylene ether anda propylene polymer is known as described in Published Japanese PatentPublication No. 56-22344, in which method a polyphenylene ether isblended with a propylene polymer having bound thereon a styrene basedmonomer by graft copolymerization. This method, however, fails toprovide a composition having excellent impact resistance.

In view of the above points, the present inventors have studiedintensively and extensively in order to develop effective technology,and as the result they have completed this invention.

SUMMARY OF THE INVENTION

Therefore, this invention provides a thermoplastic resin composition,comprising:

(a) a polyphenylene ether resin or a resin composition containing apolyphenylene ether,

(b) a modified propylene polymer, or a propylene based resin compositioncontaining the modified propylene polymer and/or a propylene polymer,and

(c) optionally, a rubbery substance, wherein the proportion of thecomponent (a) to the sum of the components (a) and (b) is 1 to 90% byweight, and that of the component (b) to the sum of the components (a)and

(b) is 99 to 10% by weight, and when the component (c) is present, theproportion of the component (c) to the sum of the components (a) and (b)is 1 to 50 parts by weight per 100 parts by weight of (a) plus (b).

DETAILED DESCRIPTION OF THE INVENTION

The polyphenylene ether used in this invention as the component (a) is apolymer obtainable by oxidative polymerization of at least one phenolcompound represented by the general formula (1) ##STR1## wherein R₁, R₂,R₃, R₄ and R₅, each represents a hydrogen atom, a halogen atom, ahydrocarbon group or a substituted hydrocarbon group, provided that oneof R₁, R₂, R₃, R₄ and R₅ is a hydrogen atom, with oxygen or anoxygen-containing gas using an oxidative coupling catalyst.

Concrete examples of the groups represented by R₁, R₂, R₃, R₄ and R₅include a hydrogen atom, chlorine, bromine, fluorine, iodine, a methylgroup, an ethyl group, an n- or iso-propyl group, a pri-, sec- ortert-butyl group, a chloroethyl group, a hydroxyethyl group, aphenylethyl group, a benzyl group, a hydroxymethyl group, a carboxyethylgroup, a methoxycarbonylethyl group, a cyanoethyl group, a phenyl group,a chlorophenyl group, a methylphenyl group, a dimethylphenyl group, anethylphenyl group, an allyl group, etc.

Concrete examples of the compounds represented by the general formula(1) include phenol, o-, m- or p-cresol, 2,6-, 2,5-, 2,4- or3,5-dimethylpheonol, 2-methyl-6-phenylphenol, 2,6-diphenylphenol,2,6-diethylphenol, 2-methyl-6-ethylphenol, 2,3,5-, 2,3,6- or2,4,6-trimethylphenol, 3-methyl-6-tert-butylphenol, thymol,2-methyl-6-allylphenol, etc. In addition, there may be used those phenolcompounds outside the scope of the general formula (1), for example,those obtainable by copolymerizing a polyhydroxy aromatic compound suchas bisphenol A, tetra-bromobisphenol A, resorcin, hydroquinone, Novolakresin, etc. with one of the compounds represented by the general formula(1).

Of the above-described phenol compounds, preferred examples includehomopolymers of 2,6-dimethylphenol (2,6-xylenol) or 2,6-diphenylphenol,or copolymers of a large amount of 2,6-xylenol and a small amount of3-methyl-6-tert-butylphenol or 2,3,6-trimethylphenol.

The oxidative coupling catalyst which can be used in the oxidativepolymerization of the phenol compounds is not limited particularly butany catalysts can be used that can catalyze such polymerizationreaction. Representative examples thereof include catalysts comprising acopper (I) salt and a tertiary amine such as copper (I)chloride-triethylamine and copper (I) chloride-pyridine, catalystscomprising a copper (II) salt, an amine and an alkali metal hydroxidesuch as copper (II) chloride-pyridine-potassium hydroxide, catalystscomprising a manganese salt and a primary amine such as manganesechloride-ethanolamine and manganese acetate-ethylenediamine, catalystscomprising a manganese salt and an alcoholate or phenolate such asmanganese chloride-sodium methylate and manganese chloride-sodiumphenolate, catalysts comprising a cobalt salt and a tertiary amine, andthe like.

It is known that the physical properties and the like of polyphenyleneethers vary depending on the reaction temperature of oxidativepolymerization to obtain the polymer, i.e., high temperaturepolymerization, which is performed at temperatures higher than 40° C.,and low temperature polymerization, which is carried out at temperaturesnot higher than 40° C., result in the production of polyphenylene etherswith different physical properties. In this invention, both the high andlow temperature polymerization reactions can be used.

The polyphenylene ethers which can be used in this invention as thecomponent (a) may include, in addition to the polyphenylene ethersdescribed above, those to which one or more styrene polymers or otherpolymers are attached by graft copolymerization. The graft copolymerscan be prepared by subjecting one or more styrene monomers and/or othermonomers to organic peroxide graft polymerization in the presence of apolyphenylene ether as described in, for example, Published JapanesePatent Publication Nos. 47-47862, 48-12197, 49-5623, 52-38596 and52-30991. Alternatively, they can also be prepared by melt-kneading thepolyphenylene ether together with the polystyrene based polymer and aradical generating agent as described in, for example, PublishedUnexamined Japanese Patent Application No. 52-142799.

The resin composition containing the polyphenylene ether as thecomponent (a) used in this invention is a resin composition comprising apolyphenylene ether and an alkenyl aromatic resin and/or rubber-modifiedalkenyl aromatic resin.

The alkenyl aromatic resin is selected from those resins which containat least 25% by weight of a polymer unit derived from a monomerrepresented by the general formula (2) ##STR2## wherein R₆, R₇, R₈, R₉and R₁₀, each represents a hydrogen atom, a halogen atom, anunsubstituted or substituted hydrocarbyl group, or an unsubstituted orsubstituted hydrocarbyloxy group, and R₁₁ represents a hydrogen atom, ora lower alkyl group having 1 to 4 carbon atoms.

Specific examples of R₆, R₇, R₈, R₉ and R₁₀ in the general formula (2)include a hydrogen atom, a halogen atom such as chlorine, bromine andiodine, a hydrocarbyl group such as a methyl group, an ethyl group, apropyl group, a vinyl group, an allyl group, a benzyl group and amethylbenzyl group, a substituted hydrocarbyl group such as achloromethyl group and a bromomethyl group, a hydrocarbyloxy group suchas a methoxy group, an ethoxy group and a phenoxy group, and asubstituted hydrocarbyloxy group such as a monochloromethoxy group.

Specific examples of R₁₁ include a hydrogen atom and a lower alkyl groupsuch as a methyl group and an ethyl group.

Specific examples of the styrene monomer include styrene,2,4-dichlorostyrene, p-methoxystyrene, p-methylstyrene, p-phenylstyrene,p-divinylbenzene, p-chloromethoxystyrene, α-methylstyrene,o-methyl-α-methylstyrene, m-methyl-α-methylstyrene,p-methyl-α-methylstyrene and p-methoxy-α-methylstyrene. They may be usedalone or in admixture. Of these, styrene is preferred.

Specific examples of the alkenyl aromatic resin include homopolymers ofstyrene monomers (e.g., styrene, chlorostyrene and α-methylstyrene) suchas polystyrene, polychlorostyrene and poly-α-methylstyrene, andcopolymers of the styrene monomers and styrene-containing monomers suchas styrene-acrylonitrile copolymer, styrene-divinylbenzene copolymer,and styrene-acrylonitrile-α-methylstyrene copolymer. Of these, preferredare homopolystyrene, styrene-α-methylstyrene copolymer,styrene-acrylonitrile copolymer, styrene-α-chlorostyrene copolymer, andstyrenemethyl methacrylate copolymer. Homopolystyrene is particularlypreferred.

The rubber-modified alkenyl aromatic resin used in this invention refersto a resin which forms a binary phase system composed of a matrix of analkenyl aromatic resin and rubber particles dispersed therein. Thisresin can be prepared by mechanically mixing a rubbery substance (c)described hereinbelow and the alkenyl aromatic resin, or by dissolvingthe rubbery substance (c) in the alkenyl aromatic monomer and thenpolymerizing the alkenyl aromatic monomer. The latter method is employedon an industrial scale in the production of impact resistantpolystyrenes. The rubber-modified alkenyl aromatic resin include also amixture of one prepared by the latter method and a rubbery substanceand/or an alkenyl aromatic resin.

The proportion at which polyphenylene ether and the alkenyl aromaticresin and/or rubber-modified alkenyl aromatic resin are mixed each othercan be varied widely, for example, in the range of 1 to 99% by weight ofthe polyphenylene ether and 99 to 1% by weight of the alkenyl aromaticresin and/or rubber-modified alkenyl aromatic resin. Within this range,optimal composition can be selected depending on the object and desiredapplication.

The propylene polymer used in this invention as the component (b) is apropylene homopolymer or a propylene copolymer. By the term "propylenecopolymer" is meant a random or block copolymer of propylene and anα-olefin having 2 to 18 carbon atoms.

Specific examples of the propylene copolymer include ethylene-propylenecopolymer, propylene-butene-1 copolymer, propylene-hexene-1 copolymer,propylene-4-methylpentene-1 copolymer, and propylene-octene-1 copolymer.

The propylene polymer may be the propylene homopolymer or the propylenecopolymer alone, or it may be a mixture of one or more of them.

As for the propylene polymer used as the component (b), appropriatepropylene polymers can be selected and used depending on commercialneeds. In particular, in the field where high thermal resistance andhigh rigidity are required, it is preferred to use a crystallinepropylene polymer composition as a propylene polymer composition of thecomponent (b), obtainable by blending a propylene polymer with a polymerof a vinylcycloalkane having at least 6 carbon atoms. It is alsopreferred to use a highly crystalline propylene polymer as the propylenepolymer. Hereinafter, the above-described propylene polymer will beexplained in greater detail.

The polymer of vinylcycloalkane (vinylcycloalkane polymer) to be blendedwith the propylene polymer means a homopolymer of vinylcycloalkane, arandom copolymer of the vinylcycloalkane and a small amount of anothervinylcycloalkane or an α-olefin, or a block copolymer of thevinylcycloalkane and an α-olefin.

The vinylcycloalkane block copolymer includes multistep copolymers ofvarious α-olefins with vinylcycloalkanes such as (1) a copolymerobtained by polymerizing a vinylcycloalkane in a first step, and thenperforming the homopolymerization of propylene in a second step, (2) acopolymer obtained by polymerizing a vinylcycloalkane in a first step,and then effecting the random copolymerization of propylene with one ormore α-olefins in a second step, and (3) a copolymer prepared byhomopolymerizing propylene in a first step, polymerizing avinylcycloalkane in a second step, and then effecting thehomopolymerization of propylene or the random copolymerization ofpropylene with one or more other α-olefins in a third step.

Of these vinylcycloalkane polymers, preferred polymers are the blockcopolymers, and more preferably the block copolymers with propylene asindicated in (1) to (3) above

Specific examples of the vinylcycloalkane having not smaller than 6carbon atoms which can be used in this invention includevinylcyclobutane, vinylcyclopentane, vinyl-3-methylcyclopentane,vinylcyclohexane, vinyl-2-methylcyclo-hexane, vinyl-3-methylcyclohexane,and vinylnorbornane. Of these, preferred are vinylcycloalkanes havingnot smaller than 8 carbon atoms.

The amount of the vinylcycloalkane unit to be blended with the propylenepolymer is such that improving effect can be achieved without changingthe inherent physical properties of the propylene polymer, and morespecifically, 0.05 to 10,000 ppm by weight, preferably 0.5 to 5,000 ppmby weight, and more preferably 0.5 to 1,000 ppm by weight.

The propylene polymer and the vinylcycloalkane polymer used in thisinvention can be advantageously prepared with a catalyst systemcomprising a titanium compound and an organoaluminium compound. As forthe titanium compound, there can be used titanium trichloride catalystscommercially available from Toyo Stoffer Co., Toho Titanium Co.,Marubeni Solvay Co., etc. Also, there can be used those catalysts whichcomprise a magnesium compound as a carrier and a titanium compound. Asfor the organo-aluminium compound, preferred is an alkylaluminiumcompound represented by formula (3)

    Al(X).sub.a (R.sub.12).sub.(3-a)                           (3)

wherein X represents a halogen atom, an alkoxy group, or a hydrogenatom, R represents an alkyl group having 1 to 18 carbon atoms, a is anumber of 0≦a<3. Specific examples of the organoaluminium includeAl(CH₃)₃, Al(C₂ H₅)₃, Al(C₂ H₅)₂ Cl, Al(C₂ H₅)₂ Br, Al(C₂ H₅)₂ (OC₂ H₅),Al(C₂ H₅)₂₋ (OC₄ H₉), Al(C₂ H₅) (OC₄ H₉)₂, Al(C₂ H₅)Cl₂, Al(C₄ H₉)₃,Al(C₄ H₉)₂ Cl, Al(C₆ H₁₃)₃, Al(C₆ H₁₃)₂ Cl, etc. and mixtures thereof.In order to improve stereoregularity, it is possible to produce thepropylene polymer and the vinylcycloalkane polymer with adding anelectron donor such as an ester of a carboxylic acid, phosphoric acid orsilicic acid.

The "highly crystalline propylene polymer" used in this invention meansa crystalline propylene polymer of which the propylene homopolymerportion or that portion in the first segment polymerized in the firststep of the block copolymer production contains aboiling-heptane-insoluble moiety having an isotactic pentad fraction ofat least 0.970, or a crystalline propylene polymer of which thepropylene homopolymer portion contains a boiling-heptane-insolublemoiety having an isotactic pentad fraction of at least 0.970, aboiling-heptane-soluble moiety in an amount of not larger than 5.0% byweight and a 20° C. xylene-soluble moiety in an amount of not largerthan 2.0% by weight.

The isotactic pentad fraction of the boiling-heptane-insoluble moiety,the content of the boiling-heptane-soluble moiety and the content of the20° C. xylene-soluble polymer can be determined as described below.

That is, after completely dissolving 5 g of the propylene polymer in 500ml of boiling xylene, the temperature of the resulting solution isdecreased to 20° C. and is left at this temperature for 4 hours,followed by filtration to separate a 20° C. xylene-insoluble moiety. Thefiltrate is concentrated to dryness to evaporate xylene and dried at 60°C. under reduced pressure to obtain a 20° C. xylene-soluble moiety. Avalue obtained by dividing this dry weight by the weight of the chargesample and expressed as percentage is defined as the content of the 20°C. xylene-soluble moiety. After drying, the 20° C. xylene-insolublemoiety is extracted with boiling n-heptane for 8 hours using Soxhletapparatus. The residue obtained is called a boiling-heptane-insolublemoiety, and a value obtained by subtracting the dry weight of the moietyfrom the weight (5 g) of the charge sample and dividing the resultingamount by the weight of the charge sample, expressed in percentage, isdefined as the content of the boiling-heptane-soluble moiety. The"isotactic pentad fraction" means the amount of isotactic linkageexpressed in pentad unit in the molecular chain of the propylenepolymer, i.e., a fraction of a propylene monomer unit present in thecenter of a linkage composed of 5 propylene monomer units continuouslybonded to each other with meso-bonding, which can be measured by using¹³ C-NMR as described in Macromolecules, 6, 925 (1973) by A. Zambelli etal. The assignment of NMR peaks, however, is determined based on theteaching of Macromolecules, 8, 687 (1975).

More particularly, the isotactic pentad fraction is measured as the areafraction of mmmm peak in total absorption peak in the region of methylcarbon in ¹³ C-NMR spectrum. The isotactic pentad fraction measured bythis method of CRM No. M19-14 Polypropylene PP/MWD/2, an NPL standardsubstance of National Physical Laboratory, United Kingdom, was 0.944.

Such highly crystalline polypropylene as described above can be preparedby methods disclosed in, for example, Published Unexamined JapanesePatent Application Nos. 60-28405, 60-228504, 61-218606, and 61-287917.

In the field where high rigidity is required, it is effective to furtherimprove the crystallinity of the crystalline propylene polymer. It ispreferred to blend a commonly used nuclei generating agent to the highlycrystalline propylene polymer. It is known that aluminium or sodiumsalts of aromatic carboxylic acids (cf. Published Unexamined JapanesePatent Application No. 58-80829), aromatic carboxylic acids, metal saltsof aromatic phosphoric acids and sorbitol derivatives (cf. PublishedJapanese Patent Publication No. 55-12460 and Published UnexaminedJapanese Patent Application No. 58-129036), for example, when added,serve as a nuclei generating agent (hereinafter, referred to as"nucleating agent") for crystals to give rise to high crystallinity.

It is also known that in addition to these nucleating agents, theabove-described vinylcycloalkane polymers having not smaller than 6carbon atoms can serve as a nucleating agent effectively as described inPublished Unexamined Japanese Patent Application No. 62-1738.

More particularly, a highly crystalline polypropylene compositionobtained by blending the vinylcycloalkane polymer having not smallerthan 6 carbon atoms with the highly crystalline propylene polymer suchthat the composition contains 0.05 to 10,000 ppm by weight of thevinylcycloalkane unit has higher crystallinity.

The highly crystalline propylene polymer and the vinylcycloalkanepolymer can be blended by a conventional method which is applied to theblending of ordinary α-olefin polymers. That is, powders of the bothpolymers, granulated pellets of the both polymers, or powder of onepolymer and granulated pellets of the other polymer are mixed with eachother with a Henschel mixer or a like mixer, and melt-kneaded with aBrabender mixer, a roll mixer, a Banbury mixer or a granulator.

The component (b) used in the resin composition in this invention is amodified propylene polymer alone, which is obtained by modifying theabove-described propylene polymer (that is, the propylene homopolymer,the propylene copolymer, the highly crystalline propylene polymer, orthe propylene polymers obtained by blending the vinylcycloalkane polymerwith the propylene polymers), or a mixture of the modified propylenepolymer and non-modified propylene polymer. If necessary or desired,various additives such as anti-oxidants, heat stabilizers, lightstabilizers, nucleating agents, lubricants, anti-static agents,inorganic or organic coloring agents, rust preventives, crosslinkingagents, foaming agents, plasticizers, fluorescent agents, surfacesmoothing agents, surface gloss improving agents, etc. may be added tothe component (b) in the production step or the processing stepthereafter.

As for the modified propylene polymer used as the component (b) in thisinvention, there can be used among others those obtained by graftcopolymerizing the above-described propylene polymer with an alkenylaromatic monomer.

The alkenyl aromatic monomer which can be used in the modification ofthe propylene polymers is one represented by the above-described generalformula (2). Of these alkenyl aromatic monomers, a styrene monomer canbe used preferably.

As for the modified propylene polymer used as the component (b) in thisinvention, there can be used a modified propylene polymer obtained bygraft copolymerizing the alkenyl aromatic monomer with one or more othermonomers copolymerizable therewith. Thermoplastic resins having highmechanical properties can be obtained by appropriately selectingmonomers with the alkenyl aromatic monomer, graft copolymerizing themwith the propylene polymer and blending.

The graft modified propylene polymer used as the component (b) in thisinvention can be obtained by graft copolymerizing a graft monomer(alkenyl aromatic monomer and if desired, one or more other monomerscopolymerizable therewith) to the propylene polymer in the presence of aperoxide, if necessary or desired.

Various known methods can be used upon grafting the graft monomer to thepropylene polymer.

For example, there can be used (i) a method in which the propylenepolymer, a graft monomer and a peroxide are mixed with each other andthe resulting mixture is melt-kneaded in a melt-kneading apparatus toeffect grafting, (ii) a method in which after the propylene polymer isdispersed in water together with the graft monomer, a peroxide is addedto the resulting dispersion in nitrogen gas atmosphere followed byheating for reaction with stirring, the reaction mixture is cooled afterthe reaction, washed by filtration and dried to obtain a graft-propylenepolymer, (iii) a method in which the propylene polymer is irradiatedwith ultraviolet ray or radioactive ray in the presence of a graftmonomer, or (iv) a method in which the propylene polymer is contactedwith oxygen or ozone in the presence of a graft monomer.

There is no particular limitation on the peroxide which is used in thepreparation of the modified propylene polymer and appropriate peroxidescan be selected freely.

For example, there can be used azo compounds such as2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4,4)-trimethylvaleronitrile,and various organic peroxides such as methyl ethyl ketone peroxide,cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide,2,2-bis(t-butylperoxy)butane, t-bytyl hydroperoxide, cumenehydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane2,5-dihydroperoxide, di-t-butyl peroxide,1,3-bis(t-butylperoxyisopropyl)benzene, 2,5-dimethyl2,5-di(t-butylperoxy)hexane, 2,5-dimethyl 2,5-di(t-butylperoxy)hexyne-3,lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, benzoyl peroxide,t-butyl peracetate, t-butyl peroxyisobutyrate, t-butyloxy pivalate,t-butyloxy-2-ethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate,t-butyl peroxylaurate, t-butyl peroxybenzoate, di-t-butylperoxyisophthalate, 2,5-dimethyl 2,5-di(benzoyl peroxy)hexane, t-butylperoxymaleate, t-butyl peroxyisopropylcarbonate, and polystyreneperoxide.

The alkenyl aromatic monomer-grafted modified propylene polymer used asthe component (b) in this invention is a resin composition comprising100 parts by weight of the propylene polymer and 0.2 to 150 parts byweights, preferably 2 to 100 parts by weight, of an alkenyl aromaticmonomer graft copolymerized thereto.

When the amount of the alkenyl aromatic monomer to be graftcopolymerized is below 0.2 part by weight, no modification effect isobserved while with that exceeding 100 parts by weight the chemicalresistance of the product decreases.

In the resin composition of this invention, the component (c), which maybe used if desired, is a rubbery substance. The "rubbery substance" usedherein refers to natural or synthetic polymer materials which areelastic at room temperature. Specific examples thereof include naturalrubber, butadiene polymers, butadiene-styrene copolymers (all the typesof copolymers inclusive of random copolymers, block copolymers, graftcopolymers, etc.) or their hydrogenated products, isoprene polymers,chlorobutadiene polymers, butadiene-acrylonitrile copolymers,isobutylene polymers, isobutylene-butadiene copolymers,isobutylene-isoprene copolymers, ethylene-acrylic acid copolymers,ethylene-propylene copolymers, ethylene-butene copolymers,ethylene-propylene-styrene copolymers, styrene-isoprene copolymers, ortheir hydrogenated products, styrene-butylene copolymers,styrene-ethylene-propylene copolymers, perfluoro rubber, fluorinerubber, chloroprene rubber, butyl rubber, silicone rubber,ethylene-propylene-nonconjugated diene copolymers, thiokol rubber,polysulfide rubber, polyurethane rubber, polyether rubber (e.g.,polypropylene oxide, etc.), epichlorohydrin rubber, polyester elastomer,polyamide elastomer, epoxy group-containing copolymers, etc.

The "epoxy group-containing copolymers" used herein refers to copolymerscomposed of an unsaturated epoxy compound and an ethylenicallyunsaturated compound.

Although no particular limitation is posed on the proportion of theunsaturated epoxy compound and the ethylenically unsaturated compoundcontained in the epoxy group-containing copolymer, usually it ispreferred that 0.1 to 50% by weight, preferably 1 to 30% by weight, ofthe unsaturated epoxy compound be copolymerized.

As for the unsaturated epoxy compound, there can be used compounds whichcontain in the molecule both an unsaturated group capable ofcopolymerizing with an ethylenically unsaturated compound, and an epoxygroup.

For example, unsaturated glycidyl esters represented by the generalformula (4) and unsaturated glycidyl ethers represented by the generalformula (5) below can be used. ##STR3## wherein R₁₃ represents ahydrocarbyl group having 2 to 18 carbon atoms and containing anethylenically unsaturated bond. ##STR4## wherein R₁₃ represents ahydrocarbyl group having 2 to 18 carbon atoms and containing anethylenically unsaturated bond, and X₁ represents ##STR5##

Specific examples thereof include glycidyl esters such as glycidylacrylate, glycidyl methacrylate and glycidyl itaconate, glycidyl etherssuch as allyl glycidyl ether, 2-methylallyl glycidyl ether, styrenep-glycidyl ether, etc.

The ethylenically unsaturated compound includes olefins, vinyl esters ofsaturated carboxylic acids having 2 to 6 carbon atoms, esters of acrylicor methacrylic acid with a saturated alcohol having 1 to 8 carbon atoms,maleic acid esters, methacrylic acid esters, fumaric acid esters, vinylhalides, styrenes, nitriles, vinyl ethers, acrylamides, etc.

Specific examples include ethylene, propylene, butene-1, vinyl acetate,methyl acrylate, ethyl acrylate, methyl methacrylate, dimethyl maleate,diethyl fumarate, vinyl chloride, vinylidene chloride, styrene,acrylonitrile, isobutyl vinyl ether and acrylamide. Of these, ethyleneis particularly preferred. Furthermore, in order to improve the impactresistance at low temperatures of the resin composition by decreasingthe glass transistion point, it is preferred to use ethylene as a secondcomponent and copolymerize therewith vinyl acetate and/or methylacrylate as a third component.

As for the rubbery substance used as the component (c) in thisinvention, there can be used any products regardless of the type ofproduction methods (e.g., emulsion polymerization methods, solutionpolymerization methods, etc.), and the type of catalysts used (e.g.,peroxides, trialkylaluminiums, lithium halides, nickel based catalysts,etc.).

Furthermore, various types of products having different degrees ofcrosslinking, different proportions of microstructures (e.g.,cis-structure, trans-structure, vinyl groups, etc.), or different meanrubber particle sizes can also be used.

In addition, various polymer rubbers such as copolymer rubbers includingrandom copolymers, block copolymers, graft copolymers, etc. can be usedas the rubbery substance in this invention. Modified products of thesecopolymers can also be used as the rubbery substance.

As for the modified copolymer rubber, there can be used, for example,those copolymers modified with one or more of styrene, unsaturateddicarboxylic acids or their anhydrides, glycidyl acrylate ormethacrylate, and carboxylic acid-containing compounds.

In this invention, one or more of the above-described rubbery substancesinclusive of their modified products can be selected and used.

Examples of the ethylene-α-olefin copolymer rubber which can be used asthe component (c) in the resin composition of this invention includecopolymer rubbers of ethylene and another α-olefin such as propylene,butene-1, pentene-1, hexene-1, 4-methylpentene-1 and octene-1, orternary copolymer rubbers such as ethylene-propylene-butene-1 copolymer.Of these, ethylene-propylene copolymer rubber and ethylene-butene-1copolymer rubber are preferred.

The ethylene content of the ethylene-α-olefin copolymer rubber is 15 to85% by weight, preferably 40 to 80% by weight. The highly crystallinecopolymer having an ethylene content of more than 85% by weight isdifficult to process under ordinary rubber molding conditions while thathaving an ethylene content of less than 15% by weight tends to sufferincrease in glass transition point (Tg), resulting in the deteriorationof rubbery properties, which is not desirable. It is preferred that theethylene-α-olefin copolymer rubber has a glass transition point of nothigher than -10° C.

Also, it is possible to use ethylene-α-olefin-nonconjugated dienecopolymer rubber as the component (c). In this case, however, thecontent of the nonconjugated diene needs to be not higher than 20% byweight. When it exceeds 20% by weight, it is disadvantageous in that theflowability of the composition is aggravated due to gelation which willoccur upon kneading.

As for the nonconjugated diene used herein, preferred are ethylidenenorbornene, dicyclopentadiene, 1,4-hexadiene, etc.

It is preferred that the number average molecular weight of thecopolymer rubber is in the range of 10,000 to 100,000, in which thecopolymer rubber is kneadable in extruders. With too small a molecularweight, the operation of the copolymer rubber upon supplying to theextruder will become difficult, and on the contrary, too large amolecular weight will decrease the flowability of the rubber, resultingin that it is difficult to process it. The Mooney viscosity (ML₁₊₄, 121°C.) of the copolymer rubber is preferably 5 to 120.

Although the molecular weight distribution of the copolymer rubber isnot limited particularly, it ranges such that Q value (i.e., weightaverage molecular weight/number average molecular weight) is preferably1 to 30, and more preferably 2 to 20.

Examples of the starting material for preparing the modifiedethylene-α-olefin copolymer which is modified with unsaturateddicarboxylic acids or their anhydrides by graft addition include maleicanhydride, maleic acid, fumaric anhydride, citraconic anhydride, etc.

The unsaturated dicarboxylic acid or its anhydride-modifiedethylene-α-olefin copolymer rubber can be prepared by known methods. Totake an example of using maleic anhydride as a modifying agent, thepreparation method is explained below. That is, maleic anhydride and afree radical initiator together with an ethylene-α-olefin copolymerrubber are added to a hydrocarbon solvent and allowed to react at 60° to150° C. for several minutes to several hours to obtain a solutioncontaining a modified rubber. In this case, alcohols, amines, etc. maybe added to convert maleic anhydride to its half ester or half amide, ifdesired. The solution thus obtained may be poured into a large amount ofmethanol, acetone, etc. to recover the modified rubber.

Alternatively, the modified copolymer rubber can be prepared by kneadingmaleic anhydride and a free radical initiator together with anethylene-α-olefin copolymer rubber in an extruder. For example, 0.5 to15 parts by weight of maleic anhydride per 100 parts by weight of therubber and 0.005 to 1.0 part by weight of the free radical initiator per100 parts by weight of the rubber are kneaded together with the rubberat 150° to 300° C. for several minutes to several tens minutes to obtaina modified copolymer rubber. If necessary or desired, gelationpreventives, for example, phenol based antioxidants such as2,6-di-t-butyl-hydroxytoluene (BHT) may be used in combination.

In this invention, various other types of modified rubbery substancesmay be used as the rubbery substance. For example, modified rubberysubstances which are modified with monomer compounds selected fromstyrene, methyl acrylate, methyl methacrylate, allyl glycidyl ether,glycidyl methacrylate, glycidyl acrylate, etc. in addition to maleicanhydride referred to above. Furthermore, rubbery substances obtained bymodifying the rubbery substance with two or more of the monomercompounds may be used. Also, two or more members selected from therubbery substance and the modified rubbery substances described abovemay be used simultaneously.

The above-described styrene monomer-grafted ethylene-α-olefin copolymerrubber can also be prepared by a method comprising dispersing in purewater minute chips or pellets of an ethylene-α-olefin copolymer rubbertogether with a dispersing agent, impregnating the copolymer rubber witha styrene monomer, and reacting them at 50° to 150° C. for 1 to 5 hoursusing a free radical initiator.

As for the rubbery substance used herein, preferred areethylene-α-olefin copolymer rubber or its modified products,ethylene-α-olefin-nonconjugated diene copolymer rubber or its modifiedproducts, styrene-butadiene random copolymer rubber,styrene-butadiene-styrene block copolymer rubber, hydrogenatedstyrene-butadiene block copolymer rubber, hydrogenatedstyrene-butadiene-styrene block copolymer rubber, etc.

The rubbery substance as the component (c) can be used in an amount of 1to 50 parts by weight per 100 parts by weight of the sum of thecomponents (a) and (b).

When the rubbery substance is contained in an amount of less than 1 partby weight, the improvement of impact resistance by the addition of therubbery substance is poor. On the other hand, with the rubbery substancein an amount of exceeding 50 parts by weight, the excellent propertieswhich polyphenylene ether has inherently are weakened, which is notdesirable.

In the thermoplastic resin composition of this invention, other highmolecular weight compounds may be added. Examples of the other highmolecular weight compounds include polyolefins (exclusive ofpolypropylene) such as polymethylpentene; homopolymers and copolymers ofvarious vinyl compounds such as polyvinyl chloride, polymethylmethacrylate, polyvinyl acetate, polyvinylpyridine, polyvinylcarbazole,polyacrylamide, polyacrylonitrile, ethylene-vinyl acetate copolymer, andalkenyl aromatic resins; polycarbonate, polysulfone, polyethyleneterephthalate, polybutylene terephthalate, polyarylene esters (e.g., Upolymer produced by Unitika Co.), polyphenylene sulfide; polyamides suchas Nylon-6, Nylon-6,6, Nylon-12, etc.; condensed high molecular weightcompounds such as polyacetals, etc. Furthermore, various thermosettingresins can be used, examples of which include silicone resins,fluorinated resins, polyimides, polyamideimides, phenol resins, alkydresins, unsaturated polyester resins, epoxy resins, diallylphthalateresins, etc.

In practicing this invention, the thermoplastic resin composition may bekneaded together with a reinforcing agent such as glass fiber or carbonfiber, an inorganic or organic filler such as carbon black, silica orTiO₂, a plasticizer, a stabilizer, a flame retardant, a dye, a pigment,etc.

More particularly, the reinforcing agent is to increase mechanical andthermal properties such as bending strength, flexural modulus, tensilestrength, modulus in tension, and heat distortion temperature when it isadmixed. Examples thereof include alumina fiber, carbon fiber, glassfiber, high modulus polyamide fiber, high modulus polyester fiber,silicon carbide fiber, titanate whisker, etc.

As for the amount of the reinforcing agent, it is sufficient that thereinforcing agent is contained in amounts effective for reinforcing thethermoplastic resin composition and usually it is preferred to use about5 to 100 parts by weight of the reinforcing agent per 100 parts byweight of the resin composition of this invention.

Particularly preferred reinforcing filler is glass, and it is preferredto use glass fiber filament composed of borosilicate glass containing arelatively small amount of sodium, which is made of gypsum and aluminiumborosilicate. This glass is known as "Σ" glass. However, in the casewhere electric properties are not so important, other glass such as oneknown as "C" glass, which contains sodium in small amounts, is alsouseful. The glass fiber filament can be produced by conventionalmethods, for example, steam or air blowing, flame blowing, andmechanical drawing. Filaments suitable for reinforcing plastics can beproduced by mechanical drawing. The diameter of the filament ranges fromabout 2 to 20 μm, which is not so strict in this invention.

In this invention, the length and form of the glass fiber filament arenot limited particularly. The filaments may be stranded intomultifilament fibers, which may then be stranded into threads, ropes orrovings. The filaments may also be woven to obtain mats. However, it isconvenient to use glass filaments cut in the form of strands about 0.3to about 3 cm, preferably about 0.6 cm or less, in length.

To be in detail on the flame retardant, those flame retardants useful inthis invention include a group of compounds well known to one skilled inthe art.

Generally, more important compounds in the known compounds are compoundscontaining elements capable of imparting flame retardance such asbromine, chlorine, antimony, phosphor and nitrogen. For example, therecan be used halogenated organic compounds, antimony oxide, a mixture ofantimony oxide and a halogenated organic compound, a mixture of antimonyoxide and a phosphor compound, a phosphor element, a phosphor compound,a mixture of a phosphor compound or a compound containing aphosphor-nitrogen bond and a halogen-containing compound, and mixturesof two or more of these.

The amount of the flame retardant is not limited particularly and it issufficient to use it in amounts effective for imparting flameretardancy. It is disadvantageous to use too much of it since thephysical properties of the resulting composition is deteriorated, i.e.,the softening point of the resin composition, for example, decreases. Anappropriate amount of the flame retardant is 0.5 to 50 parts by weight,preferably 1 to 25 parts by weight, and more preferably 3 to 15 parts byweight, per 100 parts by weight of the polyphenylene ether (a) or aresin composition containing the polyphenylene ether (a).

Useful halogen-containing compounds include those represented by thegeneral formula (6) ##STR6## wherein n is an integer of 1 to 10, R₁₄represents a member selected from the class consisting of an alkylenegroup, an alkylidene group or an alicyclic group (e.g., a methylenegroup, an ethylene group, a propylene group, an isopropylene group, anisopropylidene group, a butylene group, an isobutylene group, an amylenegroup, a cyclohexylene group, a cyclopentylidene group, etc.), an ethergroup, a carbonyl group, an amine group, a sulfur-containing group(e.g., sulfide group, sulfoxide group, sulfone group, etc.), a carbonategroup, and a phosphor-containing group.

R₁₄ may be a group which is composed of two or more alkylene oralkylidene groups bonded to each other with a group such as an aromaticgroup, an amino group, an ether group, an ester group, a carbonyl group,a sulfide group, a sulfoxide group, a sulfone group, or aphosphor-containing group. Ar and Ar' each are a monocyclic orpolycyclic carbocyclic aromatic residue such as a phenylene group, abiphenylene group, a terphenylene group, or naphthylene.

Ar and Ar' may be the same or different.

Y represents a substituent group selected from the class consisting ofan organic group, an inorganic group or an organometallic group. Thesubstituent groups represented by Y may be (1) e.g., halogen atoms suchas chlorine, bromine, iodine or fluorine, (2) an ether group representedby the general formula OE wherein E is a monovalent hydrocarbyl groupthe same as those represented by X₂ below, (3)--OH group, (4) amonovalent hydrocarbyl group, or (5) other substituent groups such as anitro group, or a cyano group. When e is 2 or more, Y's may be the sameor different.

X₂ is a monovalent hydrocarbyl group such as an alkyl group, e.g., amethyl group, an ethyl group, a propyl group, an isopropyl group, abutyl group, a decyl group, etc., an aryl group, e.g., a phenyl group, anaphthyl group, a biphenyl group, a xylyl group, a tolyl group, etc., anaralkyl group, e.g., a benzyl group, an ethylphenyl group, etc., analicyclic group, e.g., a cyclopentyl group, a cyclohexyl group, etc., ora monovalent hydrocarbyl group containing an inert substituent grouptherein. When two or more X₂ 's are used they may be the same ordifferent.

e is an integer of from 1 to a maximum number of hydrogen atoms on thearomatic ring Ar or Ar' which hydrogen atoms can be substituted. f is 0or an integer of 1 to a maximum nunber of hydrogen atoms on R whichhydrogen atoms can be substituted.

b, c and d are integers inclusive of 0. When c is not 0, neither b nor dis 0. Alternatively, only one of b and d may be 0. When c is 0, thearomatic groups are bonded to each other directly through acarbon-carbon bond. The hydroxy group or the substituent groupsrepresented by Y on the aromatic residue Ar and Ar' may be present atany desired position(s) out of ortho-, meta- and para-positions on thearomatic ring.

Specific examples of the compound represented by the general formula (6)include the following compounds:

2,2-Bis(3,5-dichlorophenyl)propane,

Bis(2-chlorophenyl)methane,

1,2-Bis(2,6-dichlorophenyl)ethane,

1,1-Bis(4-iodophenyl)ethane,

1,1-Bis(2-chloro-4-iodophenyl)ethane,

1,1-Bis(2-chloro-4-methylphenyl)ethane,

1,1-Bis-(3,5-dichlorophenyl)ethane,

2,2-Bis(3-phenyl-4-bromophenyl)ethane,

2,3-Bis(4,6-dichloronaphthyl)propane,

2,2-Bis(2,6-dichlorophenyl)pentane,

2,2-Bis(3,5-dichlorophenyl)hexane,

Bis(4-chlorophenyl)phenylmethane,

Bis(3,5-dichlorophenyl)cyclohexylmethane,

Bis(3-nitro-4-bromophenyl)methane,

Bis(4-hydroxy-2,6-dichloro-3-methoxyphenyl)methane,

2,2-Bis(3,5-dibromo-4-hydroxyphenyl)propane,

2,2-Bis(3,5-dichloro-4-hydroxyphenyl)propane, and

2,2-Bis(3-bromo-4-hydroxyphenyl)propane.

In addition, there can be used those bis-aromatic compounds whichcontain a sulfide group, a sulfoxy group, etc. in place of the twoaliphatic groups contained in the above-described specific examples, forexample, tetrabromobenzene, hexachlorobenzene, hexabromobenzene,2,2'-dichlorobiphenyl, 2,4'-dibromobiphenyl, 2,4'-dichlorobiphenyl,hexabromobiphenyl, octabromobiphenyl, decabromobiphenyl, halogenateddiphenyl ether containing 2 to 10 halogen atoms, oligomers composed of2,2-bis(3,5-dibromo-4-hydroxyphenyl)-propane and phosgene and having adegree of polymerization of 1 to 20, etc.

The halogen compound which is preferable as a flame retardant in thisinvention includes aromatic halogenated compounds such as chlorinatedbenzene, brominated benzene, chlorinated biphenyl, chlorinatedterphenyl, brominated biphenyl, and brominated terphenyl, compoundscontaining two phenyl nuclei separated by an intervening divalentalkylene group and also containing at least two chlorine or bromineatoms per one phenyl nucleus, and mixtures of two or more of theabove-described compounds. Particularly preferred are hexabromobenzene,chlorinated biphenyl or terphenyl, and mixtures thereof with antimonyoxide.

Representative phosphoric compounds which are suitably used as a flameretadant in this invention include compounds represented by the generalformula (7) and nitrogen-containing similar compounds. ##STR7## whereinQ's, which may be the same or different, each represent a hydrocarbylgroup such as an alkyl group, a cycloalkyl group, an aryl group, analkyl-substituted aryl group and an aryl-substituted alkyl group; ahalogen atom; a hydrogen atom; or a combination of these. Suitableexamples of the phosphoric acid esters include phenyl bisdodecylphosphate, phenyl bisneopentyl phosphate, phenyl ethylene hydrogenphosphate, phenyl bis(3,5,5'-trimethylhexyl) phosphate, ethyl diphenylphosphate, 2-ethylhexyl di(p-tolyl) phosphate, diphenyl hydrogenphosphate, bis(2-ethylhexyl) p-tolyl phosphate, tritolyl phosphate,bis(2-ethylhexyl) phenyl phosphate, tri(nonylphenyl) phosphate, phenylmethyl hydrogen phosphate, di(dodecyl) p-tolyl phosphate, triphenylphosphate, halogenated triphenyl phosphate, dibutyl phenyl phosphate,2-chloroethyl diphenyl phosphate, p-tolyl bis(2,5,5'-trimethylhexyl)phosphate, 2-ethylhexyl diphenyl phosphate, and diphenyl hydrogenphosphate. The most preferred phosphoric acid ester is triphenylphosphate. It is also preferred to use triphenyl phosphate together withhexabromobenzene, or triphenyl phosphate together with antimony oxide.

Other flame retardant which can be used in this invention includescompounds containing a phosphor-nitrogen bond such as phosphorus nitridechloride, phosphoric ester amide, phosphoric acid amide, phosphinic acidamide, tris(aziridinyl) phosphine oxide or tetrakis(hydroxymethyl)phosphonium chloride, etc.

There is no particular limitation on the methods of preparing the resincomposition of this invention, and ordinary known methods can be usedfor the purpose. For example, it is effective to mix the components inthe form of solutions and then evaporate the solvent or precipitate theresin in a non-solvent. On an industrial scale, however, practicalmethod for the production uses kneading the components in a meltedstate. For melt-kneading, there can be used a kneading apparatus such asmono-axial or bi-axial extruder generally used, or various types ofkneaders. High speed bi-axial extruders are particularly preferred.

Upon kneading, it is preferred to homogeneously mix the respective resincomponents in the form of powder or pellet in a tumbler, a Henschelmixer or a like apparatus. However, mixing may be omitted, if desired,and they are metered and fed separately to the kneading apparatus.

The kneaded resin composition can be molded by injection molding,extrusion molding or various other molding methods. This invention,however, includes methods in which the resin components are dry blendedupon injection molding or extrusion molding and directly kneaded duringmelt-processing operation to obtain molded articles.

In this invention, there is no particular limitation on the order ofkneading. For example, (a) the polyphenylene ether or polyphenyleneether-containing composition, (b) the propylene polymer or propylenepolymer composition, and (c) the rubbery substance may be kneaded in alump, or the components (a) and (b) may be kneaded previously followedby kneading the rubbery substance (c). Other kneading orders may also beused.

The resin composition of this invention can be molded into variousarticles such as sheets, tubes, films, fibers, laminated articles,coating materials by injection molding, extrusion molding or a likemethod. In particular, it can be used as interior or exterior fittingmaterials for automobile parts such as bumpers, instrument panels,fenders, trimms, door panels, wheel covers, side protectors, garnish,trunk lids, vonnets, roof, etc. It can also be used in machine partswhich must be heat resistant. In addition, it can be used for bicycleparts such as covering material, muffler cover, leg shield, etc.Furthermore, the resin composition of this invention can be used forelectric and electronic parts which need to have high strength and heatresistance such as housing, chasis, connectors, printed substrates,pulleys, etc.

EXAMPLES

Hereinafter, this invention will be explained in greater detail withreference to examples which should not be construed as limiting thisinvention. Tests for deflection temperature under load or heatdistortion temperature (H. D. T.), Izod impact strength (thickness: 3.2mm) were performed according to JIS K7207 and JIS K7110, respectively.Flexural modulus was determined according to ASTM D790-66 using samplesof 5.0 mm thick press molded according to JIS K6758.

EXAMPLES 1-17

The polyphenylene ether, propylene polymer, styrene-grafted propylenepolymer and styrene-grafted ethylenepropylene copolymer rubber wereprepared as follows.

Component (a): Polyphenylene Ether

In a 10 liter (l) autoclave with a jacket and equipped with a stirrer, athermometer, a condenser and an air inlet pipe reaching the bottom ofthe autoclave were charged 3,420 g of xylene, 1,366 g of methanol and1,222 g (10 mols) of 2,6-dimethylphenol and 24 g (0.6 mol) of sodiumhydroxide to obtain a homogeneous solution, to which was added asolution of 100 g of methanol having dissolved therein 31.5 g (0.3 mol)of diethanolamine, 19.4 g of (0.15 mol) of di-n-butylamine and 0.99 g(0.005 mol) of manganese chloride tetrahydrate. Then, air was blown intothe autoclave at a rate of 5 l/min. while the contents were stirredvigorously. The reaction temperature and pressure were maintained at 35°C. and 9 kg/cm², respectively. Supply of air was stopped after 7 hoursfrom the initiation of the air blowing, and the reaction mixture waspoured into a mixture of 66 g (1.15 mols) of acetic acid and 4,900 g ofmethanol. The resulting slurry was filtered under reduced pressure toisolate polyphenylene ether in a wet state. The polyphenylene ether thusisolated was washed with 7,200 g of methanol and then dried at 150° C.under reduced pressure overnight to obtain 1,179 g of polyphenyleneether in a dry state. This had a reduced viscosity of 0 54 dl/g measuredat 25° C. in 0.5 g/dl of chloroform. The polyphenylene ether thusobtained is named "A" for brevity.

Component (b): Styrene-Grafted Propylene Polymer

In a 10 l autoclave was charged pellets (1 kg) of a propylene-ethyleneblock copolymer having a melt index of 3.0 g/10 min. and an ethylenecontent of 7% by weight (trade name: SUMITOMO NOBLEN, produced bySumitomo Chemical Co., Ltd.), hereinafter called "B-1" for brevity,together with 4 l of water, 200 g of styrene monomer, 6 g of adispersing agent (METHOLOSE 90SH-100; trade name) and a peroxide(PERBUTYL PV; trade name), and allowed to react at 120° C. for about 1hour while blowing into nitrogen gas. After cooling, the reactionmixture was extracted with methyl ethyl ketone to remove polystyrene andthus styrene-grafted propylene polymer was recovered. The amount ofstyrene which was grafted to propylene polymer was 176 g. Thestyrene-grafted product thus obtained is called "B-2" for brevity.

Component (c): Styrene-Grafted Ethylene-Propylene Rubber

In a stainless steel autoclave equipped with a stirrer were charged 100parts by weight of ESPRENE E-201 (trade name for a product by SUMITOMOCHEMICAL CO., LTD.; EPM, ML₁₊₄ 121° C.=27, ethylene content=47% byweight, Tg=-64° C.; hereinafter, this rubber is called "C-1" forbrevity) as an ethylene-α-olefin copolymer rubber in the form of chips,350 parts by weight of pure water, 4.0 parts by weight of calciumtertiary phosphate and 4.0 parts by weight of PLURONIC F (trade name fora product by ASAHI DENKA CO., LTD.) and stirred with sufficient flow ofnitrogen gas.

Thereafter, 30 parts by weight of styrene monomer and 0.75 part byweight of SUNPEROX TO (trade name for a product by SANKEN KAKOU CO.,LTD.) as a free radical initiator were added to the resulting reactionmixture. After elevating the temperature to 110° C. in 80 minutes, thereaction was continued for 1 hour. After cooling, styrene-graftedcopolymer was taken out by filtration and washed sufficiently with purewater followed by drying under vacuum. Infrared absorption spectrumanalysis indicated that the styrene content of the styrene-graftedproduct was 25% by weight. Furthermore, the product had ML₁₊₄ 121° C. of53 and Tg of -58° C. Hereinafter, this rubber is called "C-2" forbrevity.

EXAMPLES 1-7

The above-described polyphenylene ether, propylene polymer, etc. werekneaded in proportions shown in Table 1 hereinbelow at a kneadingtemperature of 270° C. using LABO PLASTOMILL (produced by TOYO SEIKICO., LTD.). The resulting composition was compression-molded to formtest pieces, which were then measured for their physical properties.

The results of the tests for Izod impact strength, deflectiontemperature under load (HDT) and flexural modulus on each of the testpieces or samples are shown in Table 1 below. As will be clear fromExamples 1 to 4, the HDT values and flexural modulus values ofpolyphenylene ether and the composition composed of polypropylene andEPR rubber were low in contrast to the composition containing thestyrene-grafted propylene polymer of this invention which showedimproved Izod impact strength, HDT and flexural modulus. Remarkableimprovement in the physical properties was observed particularly in thecase where styrene-grafted ethylene-propylene rubber was blended.

From Example 4, it can be seen that the composition which had not beenblended with the rubbery substance showed very low Izod impact strength.

EXAMPLES 8 to 13

Various rubbery substances were blended with polypheneylene ether andstyrene-grafted polypropylene in proportions shown in Table 2hereinbelow. The resulting compositions were melt-kneaded using LABOPLASTOMILL and the products were measured for their physical propertiesin the same manner as in Examples 1-7. The results obtained are shown inTable 2.

EXAMPLES 14-17 Component (b): Styrene-grafted homo-polypropylene

In a 10 l autoclave was charged pellets (1 kg) of homo-polypropylenehaving a melt index of 1.0 g/10 min., a crystallization temperature of121° C. and a flexural modulus of 14,700 kg/cm² (hereinafter called"B-3" for brevity), together with 4 l of water, 350 g of styrenemonomer, 6 g of a dispersing agent (METHOLOSE 90SH-100; trade name) anda peroxide (PERBUTYL PV; trade name), and allowed to react at 120° C.for about 1 hour while blowing of nitrogen gas. After cooling, thereaction mixture was extracted with methyl ethyl ketone to removepolystyrene and thus styrene-grafted propylene polymer was recovered.The amount of styrene which was grafted to propylene polymer was 193 g.The degree of graft polymerization of the styrene-grafted product thusobtained, which was called "B-4" for brevity, was 55%.

The composition and physical properties of various polymer blendscontaining the propylene polymer (B-4), etc. are shown in Table 3hereinbelow.

From the results shown in Table 3, it can be seen that thosecompositions blended with the styrene-grafted propylene polymer aresuperior to those blended with the homo-polypropylene (no styrene-graft)in particularly their HDT and flexural modulus.

EXAMPLES 18-36

The polyphenylene ether, crystalline propylene polymer composition,styrene-grafted crystalline propylene polymer composition andstyrene-grafted ethylene-propylene copolymer rubber were prepared asfollows.

Component (a)

The same polyphenylene ether as used in Examples 1 to 17 above wasemployed.

Component (b): Crystalline Propylene Polymer (1) Synthesis ofVinylcyclohexane-Propylene Copolymer

To 100 ml of dehydrated pure n-heptane was added 1.95 g of triethylaluminium, 675 mg of ethyl p-anisate and 6.0 g of titanium compoundcatalyst prepared according to Example 1 of Published UnexaminedJapanese Patent Application No. 57-59916 in this order, and thetemperature of the mixture was elevated to 50° C. Subsequently, 50 g ofvinylcyclohexane was added to the mixture and polymerization ofvinylcyclohexane was continued for 15 minutes. The resulting polymerslurry was washed with 200 ml of n-heptane four times to remove unusedvinylcyclohexane, triethylaluminium as a cocatalyst and ethyl p-anisate.Then, n-heptane was removed from the washed active slurry bydistillation under reduced pressure to obtain 7.8 g of powder ofpolyvinylcyclohexane containing active catalyst. The amount ofpolyvinylcyclohexane polymerized is 0.30 g per g of the charged titaniumcompound catalyst.

In a stainless steel autoclave (inner volume: 5 l) was performedpolymerization of propylene using 1.06 g of the above-describedvinylcyclohexane polymerization catalyst, 0.75 g of triethyl aluminium,0.237 g of methyl p-toluylate and 1,500 ml of n-heptane under theconditions of a pressure of 6 kg/cm² gauge and a temperature of 70° C.and a hydrogen concentration of 1.5% by volume for 40 minute. Aftercompletion of the polymerization, 50 ml of n-butanol was added to stopthe polymerization and the resulting polymer slurry was taken outfollowed by the separation of polymer powder and solvent by filtration.After washing the polymer powder with 500 ml of 1N hydrochloric acid,further washing was performed with methanol until the washings becameneutral.

After drying, the powder weighed 840 g. The amount of propylenepolymerized was 1030 g per g of the titanium compound catalyst. Its [η]was 1.93 dl/g. The content of vinylcyclohexane in the copolymer powderthus obtained was 290 ppm by weight calculating from the amount ofpolymerized polymer per unit weight of the titanium compound catalystused. Hereinafter, this copolymer is called "VCP" for brevity.

(2) Crystalline Propylene Polymer

To 100 parts by weight of the homo-polypropylene (B-3) described abovewhich had a crystallization temperature of 121° C., a flexural modulusof 14,700 kg/cm² and a melt index of 1.0 were added 0.5 part by weightof the copolymer obtained in (1) above, 0.2 part by weight of BHT as astabilizing agent, 0.05 part by weight of calcium stearate, and 0.05part by weight of Irganox 1010 (trade name). After well mixing it with aHenschel mixer, the mixture was molded into pellets by a conventionalmethod using a 40 mmφ extruder.

The thus obtained crystalline propylene polymer composition, uponmeasurement for its crystallization temperature with a differentialscanning calorimeter (DSC) at a temperature decrease rate of 4° C./min.,showed 127° C. and its flexural modulus was 17,500 kg/cm². This polymercomposition is called "B-5" for brevity.

(3) Styrene-Grafted Crystalline Propylene Polymer

In a 10 l autoclave was charged pellets (1 kg) of crystallinepolypropylene obtained in (2) above, together with 4 l of water, 300 gof syrene monomer, 6 g of a dispersing agent (METHOLOSE 90SH-100; tradename) and a peroxide (PERBUTYL PV; trade name), and allowed to react at120° C. for about 1 hour while blowing of nitrogen gas. After cooling,the reaction mixture was extracted with methyl ethyl ketone to removepolystyrene and thus styrene-grafted crystalline propylene polymer wasrecovered. The amount of styrene which was grafted to propylene polymerwas 176 g. The degree of graft polymerization of the styrene-graftedproduct thus obtained was 58. This polymer is called "B-6" for brevity,

A homo-poplypropylene was recovered by the same procedures as aboveusing 1 kg of the above-described homo-polypropylene (B-3) having a meltindex of 1.0 g/min., a crystallization temperature of 121° C. and aflexural modulus of 14,700 kg/cm². The amount of styrene which wasgrafted to the homo-polypropylene was 173 g and the degree of graftpolymerization was 57%.

The degree of graft polymerization was obtained according to thefollowing equation. ##EQU1## wherein W₁ indicates the weight of thegraft polymer and W₂ indicates the weight of the charged propylenepolymer.

This styrene-grafted polypropylene is called "B-7" for brevity.

EXAMPLES 18-22

Polyphenylene ether, crystalline propylene polymer composition, etc. inproportions shown in Table 4 hereinbelow were kneaded and molded in thesame manner as in Examples 1-17, and the physical properties of themolded articles were measured.

The results on Izod impact strength, HDT and flexural modulus are shownin Table 4.

As will be clear from Table 4, the compositions comprising polyphenyleneether and homo-polypropylene had low HDT and low flexural modulus. Onthe contrary, it was observed that the compositions comprising thepropylene polymer having high crystallinity had extremely highimprovement in their HDT and flexural modulus.

Furthermore, it was observed that the impact strength of the resins wasimproved by blending the rubbery substance with polyphenylene ether andpropylene polymer.

EXAMPLES 23-28

Polyphenylene ether and styrene-grafted products of crystallinepropylene polymer composition, etc. were melt-kneaded in LABO PLASTOMILLin the same manner as in Examples 1-17, and their physical propertieswere measured.

The proportions of the components of the resins and the results on theirphysical properties are shown in Table 5.

As will be clear from Table 5, the compositions comprising polyphenyleneether and styrene-grafted products of homo-propylene polymer had low HDTand low flexural modulus. On the contrary, it was observed that thecompositions comprising polyphenylene ether and the styrene-graftedproduct of the crystalline propylene polymer had extremely highimprovement in their HDT and flexural modulus.

Furthermore, from Example 27 it can be seen that the Izod impactstrength, HDT and flexural modulus of the resins comprisingstyrene-grafted ethylene-propylene copolymer rubber as the rubberysubstance had much more improved Izod impact strength, HDT and flexuralmodulus than those containing non-styrene-grafted ethylene-propylenecopolymer rubber as the rubbery substance.

EXAMPLES 29-36

Polyphenylene ether was blended with crystalline propylene polymer, etc.and the physical properties of the product were measured. Resultsobtained are shown in Tables 6 and 7 together with the results obtainedby measuring the physical properties of blends composed of polyphenyleneether and homo-polypropylene or other resin.

The compositions obtained containing blended therewith crystallinepropylene polymer composition or its styrene-grafted product showedextremely higher HDT and flexural modulus than the compositions havingblended therewith homo-polypropylene or its styrene-grafted product.

EXAMPLES 37-46

The polyphenylene ether, highly crystalline polypropylene andstyrene-grafted highly crystalline polypropylene were obtained in thefollowing procedures.

Component (a)

The same polyphenylene ether as used in Examples 1-17 was employed.

Component (b) (1) Highly Crystalline Polypropylene

Highly crystalline propylene homopolymer was used which was preparedaccording to the slurry polymerization method described in PublishedUnexamined Japanese Patent Application No. 60-228504 and which had aninherent viscosity (measured in tetralin, 135° C.) of 2.42 dl/g, a meltflow rate of 1.6 g/10 min., a content of 20° C.-cold xylene-solubleportion of 0.6% by weight, and a content of boiling heptane-insolubleisotactic pentad fraction of 0.980. This polymer is called "B-8" forbrevity.

Then, 100 parts by weight of this polypropylene was blended with apredetermined amount of the above-described VCP copolymer (nucleatingagent), 0.2 part by weight of BHT as a stabilizing agent, 0.05 part byweight of calcium stearate, and 0.05 part by weight of Irganox 1010(trade name). After mixing the mixture with a Henschel mixer, thecomposition was molded into pellets using a 40 mmφ extruder in aconventional manner.

Further, compositions containing VCP copolymer in amounts of 0.001 partby weight, 0.05 part by weight and 0.2 part by weight, respectively wereobtained. They are called "B-9", "B-10" and "B-11", respectively.

(2) Styrene-Grafted Highly Crystalline Polypropylene

Pellets (1 kg) of the highly crystalline polypropylene (B-8) or highlycrystalline polypropylene blended with a nucleating agent was charged ina 10 l autoclave together with 4 l of water, 350 g of styrene monomer, 6g of a dispersing agent (METHOLOSE 90SH 100, trade name) and a peroxide(PERBUTYL PV, trade name), and allowed to react at 120° C. for about 1hour with blowing nitrogen gas. After washing, polystyrene was extractedwith methyl ethyl ketone and separated to recover styrene-grafted highlycrystalline polypropylene composition.

The amount of styrene grafted to the highly crystalline polypropylenewas 191 g. This styrene-grafted highly crystalline polypropylene iscalled "B-12" for brevity.

Also, the amount of styrene grafted to the highly crystallinepolypropylene (B-11) obtained by blending 0.2 part by weight nucleatingagent per 100 parts by weight of the highly crystalline polypropylene(B-8) was 182 g. This styrene-grafted highly crystalline polypropyleneis called "B-13" for brevity.

(3) Polypropylene and Styrene-Grafted Polypropylene

The polypropylene used in Examples 39, 45 and 46 were as follows.

That is, highly crystalline propylene homopolymer was used which wasprepared according to the slurry polymerization method described inPublished Unexamined Japanese Patent Application No. 60-28405 and whichhad a melt flow rate of 1.3 g/10 min., an inherent viscosity (measuredin tetralin, 135° C.) of 2.45 dl/g, a content of 20° C.-coldxylene-soluble portion of 2.9% by weight, a content of boilingheptane-soluble portion of 6.7% by weight and a content of boilingheptane-insoluble isotactic pentad fraction of 0.952. This polymer iscalled "B-14" for brevity.

Then, 100 parts by weight of this polypropylene was blended with apredetermined amount of the above-described VCP copolymer (nucleatingagent), 0.2 part by weight of BHT as a stabilizing agent, 0.05 part byweight of calcium stearate, and 0.05 part by weight of Irganox 1010(trade name). After mixing the mixture with a Henschel mixer, thecomposition was molded into pellets using a 40 mmφ extruder in aconventional manner. This polypropylene composition is called "B-15" forbrevity.

EXAMPLES 37-39

Polyphenylene ether and highly crystalline polypropylene or other resinin proportions shown in Table 8 were kneaded using LABO PLASTOMILL(produced by TOYO SEIKI CO., LTD.) at a kneading temperature of 270° C.The composition thus obtained was compression molded into test piecesand their HDT flexural modulus were measured.

The physical properties of the thus obtained thermoplastic resincompositions are shown in Table 8. It was observed that the HDT andflexural modulus were much more improved when highly crystallinepolypropylene was blended than when homo-polypropylene was blended. Evenfurther improvement in these physical properties was observed when thestyrene-grafted highly crystalline polypropylene.

EXAMPLES 40-46

Proportions and physical properties of various compositions obtained byblending polyphenylene either with a highly crystalline polypropylene, ablend of it with a nucleating agent, and a styrene-grafted highlycrystalline polypropylene or other resin together with a rubberysubstance are shown in Table 9. Improvement in HDT and flexural moduluswas observed when the highly crystalline polypropylene was blended ascompared to the case where homo-polypropylene was blended. This effectwas more marked when the highly crystalline polypropylene blended withthe nucleating agent was used. When the styrene-grafted product of thehighly crystalline polypropylene blended with the nucleating agent wasused not only the HDT and flexural modulus was improved even further butalso improvement in the Izod impact strength was noted.

EFFECT OF THE INVENTION

As described hereinabove, the thermoplastic resin compositions of thisinvention exhibit excellent effects in that they have not only goodmoldability but also they can give rise to molded articles whosephysical properties are well balanced.

Novel resin compositions provided by this invention can be processedwith ease by conventional molding methods employed for ordinarypolyphenylene ether based thermoplastic resins, for example, injectionmolding, extrusion molding, and provide products not only having wellbalanced physical properties such as impact strength, heat resistanceand hardness but also having excellent homogeneity and smoothness inappearance.

                                      TABLE 1                                     __________________________________________________________________________    Resin composition (wt %)                                                      Polyphe-   Styrene-grafted       Styrene-                                                                           Physical properties                     nylene     propylene             modified                                                                           Izod impact                                                                          Heat distortion                                                                        Modulus of              ether      polymer Polypropylene*.sup.1                                                                   EPR*.sup.2                                                                         EPR  notched                                                                              temperature                                                                            flexural                                                                      elasticity              (A)        (B-2)   (B-1)    (C-1)                                                                              (C-2)                                                                              (kg · cm/cm)                                                                (4.6 kg/cm.sup.2,                                                             °C.)                                                                            (kg/cm.sup.2)           __________________________________________________________________________    Example 1                                                                           48   48      0        4    0    10     153      16,300                  Example 2                                                                           48    0      48       4    0     4     136      13,800                  Example 3                                                                           48   48      0        0    4    13     155      17,100                  Example 4                                                                           50   50      0        0    0     2     157      17,300                  Example 5                                                                           45   45      0        10   0    16     146      15,400                  Example 6                                                                           45    0      45       10   0     6     128      12,900                  Example 7                                                                           45   45      0        0    10   21     152      17,100                  __________________________________________________________________________     *.sup.1 Sumitomo Noblen AH561 (Trade name, produced by Sumitomo Chemical      Co., Ltd.)                                                                    *.sup.2 Sumitomo Esprene E201 (Trade name, produced by Sumitomo Chemical      Co., Ltd.; ML.sub.1+4 121° C. =  27)                              

                                      TABLE 2                                     __________________________________________________________________________           Resin composition (wt %)     Physical properties                              Polyphenylene                                                                         Styrene-grafted      Izod impact                                                                           Heat distortion                                                                        Modulus of                      ether   propylene polymer    notched temperature                                                                            flexural elasticity             (A)     (B-2)      Rubbery substance                                                                       (kg · cm/cm)                                                                 (4.6 kg/cm.sup.2,                                                                      (kg/cm.sup.2)            __________________________________________________________________________    Example 8                                                                            42      42         EPR (C-1)*.sup.1                                                                        17      140      14,300                                             16                                                  Example 9                                                                            42      42         Styrene-modified                                                                        22      143      15,100                                             EPR (C-2)                                                                     16                                                  Example 10                                                                           42      42         SBR*.sup.2                                                                               8      131      13,100                                             16                                                  Example 11                                                                           42      42         EPR*.sup.3                                                                              10      138      14,100                                             16                                                  Example 12                                                                           42      42         Polybutadiene*.sup.4                                                                     9      128      12,700                                             16                                                  Example 13                                                                           42      42         SEP*.sup.5                                                                              29      121      11,800                                             16                                                  __________________________________________________________________________     *.sup.1 Sumitomo Esprene E201 (Trade name, produced by Sumitomo Chemical      Co., Ltd.; ML.sub.1+4 121° C. = 27)                                    *.sup.2 Sumitomo SBR 1507 (Trade name, produced by Sumitomo Chemical Co.,     Ltd.)                                                                         *.sup.3 Etylenepropylene copolymer rubber (ML.sub.1+4 121° C. =        123)                                                                          *.sup.4 Diene 35A (Trade name, produced by Asahikasei Co., Ltd.)              *.sup.5 KRATON GX1701 [Trade name, produced by Shell Chemical Co., Ltd.;      styreneethylene-propylene copolymer (styrene content 35 wt %)            

                                      TABLE 3                                     __________________________________________________________________________    Resin composition (parts by weight)  Physical properties                      Polyphenylene Styrene-grafted                                                                         Homo-    Espren                                                                            Izod impact                                                                          Heat distortion                                                                         Modulus of              ether         propylene polymer                                                                       polypropylene                                                                          E201                                                                              notched                                                                              temperature                                                                             flexural                                                                      elasticity              (A)           (B-4)     (B-3)    (C-1)                                                                             (kg · cm/cm)                                                                (4.6 kg/cm.sup.2,                                                                       (kg/cm.sup.2)           __________________________________________________________________________    Example 14                                                                          50      50         0        0  4.3    168       18,900                  Example 15                                                                          50      50         0       10  12.9   154       15,100                  Example 16                                                                          50       0        50        0  3.1    152       16,300                  Example 17                                                                          50       0        50       10  9.7    142       12,900                  __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________    Resin composition (parts by weight)                                           Polyphe-   Styrene-grafted   Ethylene-                                                                              Physical properties                     nylene     crystalline propylene                                                                    Homo-  propylene*.sup.1                                                                       Izod impact                                                                          Heat distortion                                                                        Modulus of              ether      polymer composition                                                                      poly-  copolymer rubber                                                                       notched                                                                              temperature                                                                            flexural                                                                      elasticity              (A)        (B-6)      propylene                                                                            (C-1)    (kg · cm/cm)                                                                (4.6 kg/cm.sup.2,                                                             °C.)                                                                            (kg/cm.sup.2)           __________________________________________________________________________    Example 18                                                                          41   59         0      0        4      150      22,300                  Example 19                                                                          41   59         0      8        12     138      19,500                  Example 20                                                                          41   0          (B-3) 59                                                                             0        4      137      17,600                  Example 21                                                                          41   0          (B-3) 59                                                                             8        10     121      15,200                  Example 22                                                                          41   0          (B-5) 59                                                                             0        2      144      20,100                  __________________________________________________________________________     *.sup.1 Esprene E201 (Trade name, produced by Sumitomo Chemical Co., Ltd.

                                      TABLE 5                                     __________________________________________________________________________    Resin composition (parts by weight)                                           Polyphe-   Styrene-grafted      Ethylene-                                                                           Physical properties                     nylene     crystalline propylene                                                                    Styrene-grafted                                                                         propylene                                                                           Izod impact                                                                          Heat distortion                                                                        Modulus of              ether      polymer    homo-polypropylene                                                                      copolymer                                                                           notched                                                                              temperature                                                                            flexural                                                                      elasticity              (A)        (B-6)      (B-7)     rubber                                                                              (kg · cm/cm)                                                                (4.6 kg/cm.sup.2,                                                             °C.)                                                                            (kg/cm.sup.2)           __________________________________________________________________________    Example 23                                                                          41   59          0        0      6     157      23,500                  Example 24                                                                          41   59          0         .sup. (C-1) 8                                                                      16     149      20,600                  Example 25                                                                          41    0         59        0      6     136      18,200                  Example 26                                                                          41    0         59         .sup. (C-1) 8                                                                      13     126      15,900                  Example 27                                                                          41   59          0        (C-2)*.sup.1 8                                                                      20     153      21,900                  Example 28                                                                          41    0         59        (C-2)*.sup.1 8                                                                      11     129      17,100                  __________________________________________________________________________     *.sup.1 Grafted product of Esprene E201 (Trade name, produced by Sumitomo     Chemical Co., Ltd.)                                                      

                                      TABLE 6                                     __________________________________________________________________________    Resin composition (wt %)                                                      Polyphe-   crystalline                Physical properties                     nylene     propylene                                                                           Homo-                Izod impact                                                                          Heat distortion                                                                        Modulus of              ether      polymer                                                                             polypropylene                                                                         Rubbery      notched                                                                              temperature                                                                            flexural                                                                      elasticity              (A)        (B-5) (B-3)   substance*.sup.1                                                                    Polyamide*.sup.2                                                                     (kg · cm/cm)                                                                (4.6 kg/cm.sup.2,                                                             °C.)                                                                            (kg/cm.sup.2)           __________________________________________________________________________    Example 29                                                                          39   55     0      6      0     13     148      19,800                  Example 30                                                                          31   41     0      0     28      5     160      21,500                  Example 31                                                                          39    0    55      6      0     13     129      16,900                  Example 32                                                                          31    0    41      0     28      4     145      19,700                  __________________________________________________________________________     *.sup.1 Styrenebutadiene copolymer rubber; Cariflex TR1116 (Trade name,       produced by General Electric Co., Ltd.)                                       *.sup.2 Nylon6, A1020BRL (Trade name, produced by Unitika Co., Ltd.)     

                                      TABLE 7                                     __________________________________________________________________________    Resin composition (wt %)                                                      Polyphe-   Styrene-grafted                                                                       Styrene-grafted    Physical properties                     nylene     crystalline                                                                           homo-   Espren     Izod impact                                                                          Heat distortion                                                                        Modulus of              ether      propylene                                                                             polypropylene                                                                         E201       notched                                                                              temperature                                                                            flexural                                                                      elasticity              (A)        polymer (B-6)                                                                         (B-7)   (C-1)                                                                             Polystyrene*.sup.1                                                                   (kg · cm/cm)                                                                (4.6 kg/cm.sup.2,                                                             °C.)                                                                            (kg/cm.sup.2)           __________________________________________________________________________    Example 33                                                                          39   55       0      6    0     15     150      21,500                  Example 34                                                                          31   41       0      0   28      5     164      23,200                  Example 35                                                                          39    0      55      6    0     14     133      17,300                  Example 36                                                                          31    0      41      0   28      4     147      21,600                  __________________________________________________________________________     *.sup.1 Esbrite 8 (Trade name, produced by Sumitomo Chemical Co., Ltd.)  

                                      TABLE 8                                     __________________________________________________________________________           Resin composition (wt %)                                                                        Styrene-grafted   Physical properties                       Polyphenylene                                                                          Highly crystalline                                                                     highly crystalline                                                                              Heat distortion                                                                         Modulus of                      ether    polypropylene                                                                          polypropylene                                                                          Polypropylene                                                                          temperature                                                                             flexural elasticity             (A)      (B-8)    (B-12)   (B-14)   (4.6 kg/cm.sup.2,                                                                       (kg/cm.sup.2)            __________________________________________________________________________    Example 37                                                                           43       57       0        0        162       17,300                   Example 38                                                                           43       0        57       0        171       18,200                   Example 39                                                                           43       0        0        57       148       15,900                   __________________________________________________________________________

                                      TABLE 9                                     __________________________________________________________________________    Resin composition (parts by weight)                                           Polyphe-   Highly                                                                              Styrene-grafted      Physical properties                     nylene     crystalline                                                                         highly crystalline                                                                           Rubbery                                                                             Izod impact                                                                          Heat distortion                                                                        Modulus of              ether      polypro-                                                                            polypropylene                                                                          Polypro-                                                                            substance*.sup.1                                                                    notched                                                                              temperature                                                                            flexural                                                                      elasticity              (A)        pylene                                                                              (B-13)   pylene                                                                              (C-1) (kg · cm/cm)                                                                (4.6 kg/cm.sup.2,                                                             °C.)                                                                            (kg/cm.sup.2)           __________________________________________________________________________    Example 40                                                                          40    (B-8) 50                                                                           0        0     10    7      143      16,500                  Example 41                                                                          40    (B-9) 50                                                                           0        0     10    8      147      16,800                  Example 42                                                                          40   (B-10) 50                                                                           0        0     10    6      151      17,400                  Example 43                                                                          40   (B-11) 50                                                                           0        0     10    5      159      19,100                  Example 44                                                                          40   0     (B-13) 50                                                                              0     10    19     164      21,800                  Example 45                                                                          40   0     0        (B-14) 50                                                                           10    6      135      14,800                  Example 46                                                                          40   0     0        (B-15) 50                                                                           10    5      146      16,700                  __________________________________________________________________________     *.sup.1 Sumitomo Esprene E201 [Trade name, produced by Sumitomo Chemical      Co., Ltd.; ML.sub.1+4 121° C. = 27, ethylenepropylene copolymer        rubber (propylene content 53 wt %)                                       

What is claimed is:
 1. A thermoplastic resin composition consistingessentially of:(a) a polyphenylene ether, (b) an alkenyl aromaticmonomer-grafted propylene polymer, and (c) a rubbery substance.
 2. Athermoplastic resin composition as claimed in claim 1, wherein saidrubbery substance (c) is at least one selected from the group consistingof ethylene-α-olefin copolymer rubber, modified products ofethylene-α-olefin copolymer rubber, ethylene-α-olefin-nonconjugateddiene copolymer rubber, modified products ofethylene-α-olefin-nonconjugated diene copolymer rubber,styrene-butadiene random copolymer rubber, styrene-butadiene-styreneblock copolymer rubber, hydrogenated styrene-butadiene block copolymerrubber and hydrogenated styrene-butadiene-styrene block copolymerrubber.
 3. A thermoplastic resin composition as claimed in claim 2,wherein said rubbery substance (c) is said ethylene-α-olefin copolymerrubber which is an ethylene-propylene copolymer rubber which has anethylene content of 15 to 85% by weight, a Mooney viscosity (ML₁₊₄ 121°C.) of 5 to 120, and a glass transient point of not higher than -10° C.4. A thermoplastic resin composition as claimed in claim 1, wherein saidpolyphenylene ether (a) is a polyphenylene ether obtained by theoxidative coupling polymerization of at least one phenol compoundrepresented by the general formula ##STR8## wherein R₁, R₂, R₃, R₄ andR₅, each represents a hydrogen atom, a halogen atom, a hydrocarbyl groupor a substituted hydrocarbyl group, a hydrocarbyloxy group or asubstituted hydrocarbyloxy group provided that one of R₁, R₂, R₃, R₄ andR₅ is always a hydrogen atom.
 5. A thermoplastic resin composition asclaimed in claim 1, wherein said component (c) is an alkenyl aromaticmonomer-grafted rubbery substance.
 6. A thermoplastic resin compositionas claimed in claim 1, wherein said alkenyl aromatic monomer-graftedpropylene polymer is obtained by grafting an alkenyl aromatic monomeronto a highly crystalline propylene homopolymer or block copolymer ofpropylene having a boiling heptane-insoluble portion, which has anisotactic pentad fraction of at least 0.970.
 7. A thermoplasticcomposition as claimed in claim 6, wherein said propylene homopolymer orsaid block copolymer has a boiling heptane-soluble portion content ofnot higher than 5.0% by weight and a xylene-soluble portion content ofnot higher than 2.0% by weight at 20° C.
 8. A thermoplastic resincomposition consisting essentially of:(a) a polyphenylene ether, (b) analkenyl aromatic monomer-grafted propylene polymer, and (c) a rubberysubstance; wherein the proportion of the component (a) to the sum ofcomponent (a) and (b) is 1 to 90% by weight, the proportion of component(b) to the sum of components (a) and (b) is 99 to 10% by weight, and theproportion of component (c) to the sum of components (a) and (b) is 1 to50 parts by weight per 100 parts by weight of (a) plus (b).
 9. Athermoplastic resin composition as claimed in claim 8,wherein saidcomponent (a) is a polyphenylene ether obtained by the oxidativecoupling polymerization of at least one phenol compound represented bythe general formula ##STR9## wherein R₁, R₂, R₃, R₄ and R₅ eachrepresents a hydrogen atom, a halogen atom, a hydrocarbyl group, asubstituted hydrocarbyl group, a hydroxycarbyloxy group or a substitutedhydrocarbyloxy group provided that one of R₁, R₂, R₃, R₄ and R₅ isalways a hydrogen atom; wherein the alkenyl aromatic monomer ofcomponent (b) is a monomer represented by the general formula ##STR10##wherein R₆, R₇, R₈, R₉ and R₁₀ each represent a hydrogen atom, a halogenatom, an unsubstituted or substituted hydrocarbyl group, or anunsubstituted or substituted hydrocarbyloxy group, and R₁₁ represents ahydrogen atom, or a lower alkyl group having 1 to 4 carbon atoms; andwherein said component (c) is at least one member selected from thegroup consisting of ethylene-α-olefin copolymer rubber, modifiedproducts of ethylene-α-olefin copolymer rubber,ethylene-α-olefin-nonconjugated diene copolymer rubber, modifiedproducts of ethylene-α-olefin-nonconjugated diene copolymer rubber,styrene-butadiene random copolymer rubber, styrene-butadiene-styreneblock copolymer rubber, hydrogenated styrene-butadiene block copolymerrubber and hydrogenated styrene-butadiene-styrene block copolymerrubber.
 10. A thermoplastic resin composition as claimed in claim 9,wherein said phenol compound of said component (a) is selected from thegroup consisting of phenol, o-cresol, m-cresol, p-cresol,2,6-dimethylphenol, 2,5-dimethylphenol, 2,4-dimethylphenol,3,5-dimethylphenol, 2-methyl-6-phenylphenol, 2,6-diphenylphenol,2,6-diethylphenol, 2-methyl-6-ethylphenol, 2,3,5-trimethylphenol,2,3,6-trimethylphenol, 2,4,6-trimethylphenol,3-methyl-6-tert-butylphenol, thymol, and 2-methyl-6-allylphenol.
 11. Athermoplastic resin composition as claimed in claim 9, wherein saidcomponent (a) is selected from the group consisting of homopolymers of2,6-dimethylphenol, homopolymers of 2,6-diphenylphenol, copolymers of2,6-dimethylphenol and 3-methyl-6-tert-butylphenol, and copolymers of2,6-dimethylphenol and 2,3,6-trimethylphenol.
 12. A thermoplastic resincomposition as claimed in claim 8, wherein said component (c) is analkenyl aromatic monomer-grafted rubbery substance.
 13. A thermoplasticresin composition as claimed in claim 8, wherein said alkenyl aromaticmonomer-grafted propylene polymer is obtained by grafting an alkenylaromatic monomer onto a highly crystalline propylene homopolymer orblock copolymer of propylene having a boiling heptane-insoluble portion,which has an isotactic pentad fraction of at least 0.970.